Rare Earth Precursors for Stable, Low-Impurity ALD/CVD Films
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rare earth precursors face challenges with thermal stability, volatility, and reactivity issues, limiting their effectiveness in deposition processes such as ALD and CVD, particularly for high-k materials in semiconductor devices.
Innovation Solution
Development of heteroleptic rare earth precursors containing alkoxide, amide, and alkyl ligands, specifically compounds represented by Formula 1, which enhance thermal stability and reactivity with reactive gases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If typical rare earth precursors (amides, amidinates, β-diketonates, cyclopentadienyl) are used, then deposition can be performed, but the precursors have high melting points, low deposition temperatures, large amounts of impurities in thin films, and relatively low reactivity
Solution Approach 1:
The patent changes the chemical parameters of the precursor by introducing heteroleptic ligand combinations (amide, amidinate, β-diketonate, cyclopentadienyl in various ratios) to improve volatility and reduce decomposition temperature, thereby reducing carbon impurity production while maintaining deposition effectiveness
Solution Approach 2:
The patent uses composite ligand structures combining multiple types of ligands (amide, amidinate, β-diketonate, cyclopentadienyl) around the rare earth metal center to create precursors that balance thermal stability, volatility, and reactivity, reducing impurity formation during deposition
2Reliability
If lanthanide 2,2,6,6-tetramethylheptanedionate or lanthanide 2,2,7-trimethyloctanedionate is used, then deposition can proceed, but the high melting points (260°C or higher, 197°C) limit process flexibility
Solution Approach 1:
The patent modifies the molecular structure parameters by introducing heteroleptic ligand combinations with different steric and electronic properties, which lowers the melting point and decomposition temperature of the precursors, enabling deposition at lower temperatures and improving process flexibility
3Reliability
If β-diketonate ligands are used, then deposition can be performed, but delivery efficiency is difficult to control, growth rate is low, and purity is low due to high carbon impurity production rate
Solution Approach 1:
The patent optimizes the ligand composition parameters by combining β-diketonate with other ligand types (amide, amidinate, cyclopentadienyl) in heteroleptic structures, which improves volatility and delivery efficiency while enhancing reactivity to increase growth rate and reduce carbon impurity production
4Ease of operation
If cyclopentadienyl compounds are used, then liquid compounds can be obtained, but high carbon impurity content in thin films is produced during process evaluation
Solution Approach 1:
The patent modifies the ligand composition parameters by using cyclopentadienyl in combination with other ligand types rather than as a sole ligand, which reduces the carbon impurity content in the deposited film while maintaining the liquid compound form and ease of handling
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The new precursors enable uniform thin film deposition with improved physical properties, thickness, and step coverage, suitable for ALD and CVD processes, addressing the limitations of existing precursors.
Implementation Method 1
a vapor deposition compound capable of implementing thin film deposition through vapor deposition
Implementation Method 2
applicable to atomic layer deposition (ALD) or chemical vapor deposition (CVD)
Implementation Method 3
applicable to atomic layer deposition (ALD) or chemical vapor deposition (CVD)
Data Source
AI summary
The present disclosure relates to a compound capable of implementing thin film deposition through vapor deposition, and more particularly, to a rare earth compound which is applicable to atomic layer deposition (ALD) or chemical vapor deposition (CVD) and has excellent thermal stability and reactivity, a rare earth precursor containing the same, a method of preparing the same, and a method of forming a thin film using the same.